The present disclosure generally relates to a diaphragm-type gas meter for determining the usage of a gas product. More specifically, the present invention relates to an improved diaphragm for use in a diaphragm-type gas meter to provide more consistent metering and extended diaphragm life.
Positive displacement gas meters have long been used to determine the amount of gas usage by a consumer. Particularly, where gas flow rates are relatively low, such as at the gas inlets of homes and small buildings, diaphragm meters are used to measure gas consumption. Diaphragm meters are connected to a supply pipe that delivers pressurized gas from an external source. An outlet pipe runs from the diaphragm gas meter to the inside of the house or building to supply the metered gas to the building.
When a gas burning device, such as a stove or furnace, is activated, gas begins to flow into the enclosed housing of the meter. Diaphragm meters measure the amount of gas consumed in the following manner. Initially, a valve in the diaphragm meter is in a first position in which gas flows into the enclosed housing on one side of the diaphragm enclosed within the diaphragm meter. As the first side of the diaphragm expands outward due to the pressure of the gas flowing into the enclosed housing, gas on the opposite side of the diaphragm is forced out of the diaphragm meter to the outlet pipe. As the diaphragm moves due to the pressure of gas from the supply, the diaphragm rotates the flag axle with an arm attached to one end. The arm forces the metering components within the meter to move, which rotates dials to indicate the amount of gas usage. The flag axle also has a crankshaft attached to an arm that moves internal valving within the diaphragm meter. Movement of the valving uncovers another passage that exposes the opposite side of the diaphragm to the pressurized gas. Thus, as gas is continually used by the consumer, the diaphragms reciprocate between two different positions, where each movement causes a dial within the meter to rotate to indicate gas consumption.
As the above description indicates, the diaphragms within the diaphragm-type gas meter continuously reciprocate between extended and retracted positions. This movement of each the diaphragm must be consistent to provide a repeatable volume displacement for an accurate reading by the gas meter. Further, since gas meters are typically left in the field for numerous years, the diaphragm must be durable over the life period of the gas meter.